Nope... As a matter of fact I've probably decreased it a bit. Adding longer barrels, more weight (due to cosmetic mods), changes some of the physics of a paintball gun. I've had to up the velocity on the really long barrels to get the paint out, and the bigger guns are tough to move fast with.
I usually play with the shorter mod ones, 12" to 16" barrels.
Now in defense of "Performance Improvments" and my mods, the PEC MASTER never really needed any "Improved Performance" to begin with. The stock 12" ported barrels have been about the most accurate I've ever shot. Especially out of the box. They will practically shoot liquid Co2 so reliability has also been exceptional. I cannot think of any performance improvement needed for milsim or woodsball (games I play) that would help me any more. The ported extensions I've made seem to help stabilize each shot, and the butt stock helps steady my aim. I use the sights on the guns, and hit what I aim at, usually.
Here is one with a 14" barrel and a 7" ported extension. The extension is 4" down the (top) of the barrel so the ball exits right behind the ports in the extension. It may offer a marginal improvement, but I made it mostly for looks.